The quality of computer animation depends largely on its ability to convey a sense of realism so that the animated figures on the screen resemble the actions of real people and animals. Excellent computer generated animation programs are capable of portraying animated human-like characters which convey and perform human-like emotions and movements. The greater the sense of realism exhibited by an animated character, for example, emotionally interactive image puppets, the more the computer animation program is desired and appreciated by the using public
In order for the animated characters to be able to convey and perform a wide variety of human-like emotions and movements, the computer programmer is generally obligated to write a separate subroutine (module) for every emotion or movement desired to be incorporated in the animated character's persona.
Due to mass storage and feasibility constraints of presently commercially available digital computer systems, computer programmers can only simulate in animated characters a very limited number of emotions. These emotions are the same for each individual animated character and thus the animation program lacks a sense of realism.
Emotional expressiveness denotes the capability of the animated character to simulate human emotions, such as happiness, sadness, sarcasm, and inquisitiveness. Since it is very difficult to exhibit emotion in an animated character, computer programmers have concentrated on giving animated characters the ability to move and interact somewhat like humans. By utilizing vector and matrix mathematics, computer programmers have managed to incorporate into animated characters a few basic kinematic (movement) characteristics, such as translate, rotate, swivel and scale. (See, e.g., Girard et al., "Computational Modeling for the Computer Animation of Legged Figures; Siggraph '85 Proceedings, Vol. 19, No. 3, 1985, pp. 263-270). In addition, computer programmers have managed to incorporate a few human-like gestures into the animated characters. For example, when a human is explaining something, his/her arms may wave about in a particular way. However, most computer animation packages lack the capability of conveying "emotional expressiveness" to the animated character, indicative of the movements or gestures portrayed.
An objective shared by many computer programmers is to have each animated character exhibit a large number of individualistic emotions which correspond to the character's physical gestures.
Therefore, it is an object of the present invention to create animated characters which have the capability of conveying human-like emotions and movements and/or gestures portrayed in order to convey a sense of realism. A further objective of the present invention is to provide a method for conveying a smooth transition from one gesture to another.
An additional object of the present invention is to provide the animator with the capability of simulating a large number of emotions and movements without having to write a separate subroutine (module) for each emotion and movement.
A further object of the present invention is to portray animated video and/or movie characters having good visual representations of the expressiveness of human emotion together with real-time responsiveness.
Still another object of the present invention is to portray animated video and/or movie characters as sensitive to their surroundings, so that, for example, the characters successfully avoid obstacles and navigate openings such as doors.
An additional object of the present invention is to provide a means for restricting character movements, for example, requiring a character to face forward at various times.
These and other objects of the present invention become more apparent in the following sections.